The relationship between magnesium and osteoarthritis of knee: A MOOSE guided systematic review and meta-analysis

The impact of magnesium on risk of knee osteoarthritis (KOE) is still under investigation. This meta-analysis evaluated the relationship between magnesium and risk of KOE. A comprehensive search was performed to identify retrospective cohort study or cross-sectional study of the association between magnesium and KOE from the Cochrane library, PubMed, and Embase. The search time limit was from the establishment of the database to December 2018. Two evaluators selected the literature, extracted the data, and evaluated the quality of the literature according to the inclusion and exclusion criteria, independently. Meta-analysis was performed using RevMan 5.3 software and publication bias was assessed using Begg and Egger test and funnel plot. Finally, 6 studies were included with a total of 15,715 participants. Although higher daily intake of magnesium was associated with a significantly reduced risk of fracture in patients with KOE (OR = 0.66, 95%CI: 0.56, 0.78; P < .00001), it was not significant for lowering the risk of KOE (OR = 0.80; 95% CI: 0.61, 1.04; P = .1). Meta-analysis also showed that population with higher serum magnesium levels had significantly lower risk of KOE (odds ratio (OR) = 0.84; 95% confidence interval (CI): 0.72, 0.98; P = .03). Further subgroup analysis showed that the relationship between serum magnesium level and KOE risk was significantly affected by serum magnesium level (P = .006 for quartiles 4 vs 1). Higher level of magnesium intake was not associated with lower risk of KOE. However, higher daily intake of magnesium may be inversely associated with risk of fracture in KOE patients.